Currently, a display device usually includes a substrate which has a very high requirement on surface accuracy thereof to prevent adverse affect on picture display quality of the display device due to insufficient surface accuracy of the substrate (such as, scratches, foreign substances or the like on the surface of the substrate). However, during manufacturing of a display device, for example, when a substrate is being transferred, surface of the substrate may be easily scratched locally, i.e., partial scratches may be generated on the surface of the substrate.
In order to remove partial scratches on surface of a substrate to improve picture display quality of the display device, presently and usually, a substrate grinding device is utilized to perform an entire grinding on the surface of the substrate where partial scratches lie, so as to remove the partial scratches on the surface of the substrate and improve picture display quality of the display device. However, removing partial scratches on the surface of the substrate in the above manner will reduce an overall thickness of the substrate, and if the substrate having a reduced thickness is assembled in a display device, assembling accuracy of the display device is reduced.